This project represents Phase I of a combined Phase I/Phase II STTR proposal to develop a telerobotic surgical system with an integrated robot-assisted laparoscopic ultrasound (LUS) capability, based upon Intuitive Surgical's da Vinci(r) robot and upon ongoing research at Intuitive Surgical and Johns Hopkins University (JHU). The project uses laparoscopic liver cancer surgery as a focusing application in both phases, although the broader aim is development of a versatile system that is useful for many procedures. The proposed work will develop robot-assisted laparoscopic ultrasound integrated into the da Vinci surgical robot system, for application to cancer staging, biopsy, ablative therapy, and resection, in order to make these procedures significantly more accurate, more effective, and less expensive. Phase I specific aims include: 1) integration of an ultrasound probe with da Vinci, 3D image generation from scanned 2D images, ultrasound probe tracking, calibration, and image presentation; 2) development of robot probe manipulation behaviors to be carried out under the surgeon's supervisory control; and 3) evaluation of the Phase I system capabilities to determine quantitative performance and assess user acceptability. At the end of Phase I, the surgeon will be able to manually control the ultrasound probe being held by da Vinci to acquire 2D ultrasound slices calibrated and registered in the endoscopic camera frame. A client workstation (the "Intelligent Controller") communicating with da Vinci will assemble these 2D slices into a 3D ultrasound image that da Vinci will display in the 3D display in its surgeon console, side-by-side with the video endoscope image. The Phase I system will have a limited ability to actively assist the surgeon in making 3D scans, primarily a "rocking" behavior in which the LUS probe is rotated on its axis and possibly a "lawn mowing" behavior in which the LUS probe is swept along a surgeon defined path. Performance and clinical usefulness will have been assessed using phantom and animal cadaver experiments.